Children (everyone actually) see a lot of real people online, on their virtual classes, zoom, facetime, etc etc.
In day to day life, I rarely see people, or animals get pushed or injured, but when I see it happening in the news, I know it's real. So would children.
When we hear someone online telling us something that happened to them, or a story with a lesson, we know it's really happening. Especially if the person telling us is sitting right on the "other side" of our screen, and we're talking directly to each other.
Also, throughout the ages lots of families were raised in an area that might be just a few miles from the nearest village/town/neighbor, and we might not visit them, or go to get supplies, for weeks or months at a time.
Those ppl, including the kids, had the knowledge these people a few miles from them (or hundreds) were real people.
I can see children as getting to read subtle facial expressions of the eyes and body to get what's going on.
I can't speak for other countries, but frankly I get kinda disgusted at so many Americans need to produce these overblown facial expressions. The giant overdone grins, the faux shocked looks. If one's face is more placid, they're often asked "What's wrong?"
I don't think kids are going to lose the ability to know there's a real person behind the mask.
How do people, including children who are blind keep from dehumanizing ppl?